1. Field of the Invention
This invention relates to an incubator for chemical-analytical slides which are utilized for quantitative analysis of various components in a body fluids such as blood and urine.
2. Description of Prior Arts
In the past, various components such as glucose, bilirubin or urea nitrogen in a body fluid were determined by placing a sample of the body fluid in a test tube and adding liquid reagent(s) prepared according to the components. However, there are some problems in this method. That is, a good deal of a body fluid sample such as human blood which is precious is necessary, its procedure is troublesome so that simple and rapid measurement is difficult, continuous measurement of many samples is difficult, and so on. In order to solve these problems, the analysis in dry process using a chemical-analytical slide cotaining all the reagents necessary for the analysis is widely utilized.
Such analytical slide is typically, as illustrated in FIG. 9, in which the chemical slide 1 is shown, composed of a multilayer analytical element 2 and a slide frame 5. The multilayer analytical element 2 is usually composed of a transparent film layer, a reagent layer, a reflecting layer and a spreading layer laminated in this order. The slide frame 5 admits this multilayer analytical element 2, and an opening for spotting a liquid sample 3 is formed on the upper side while an opening for photometry 4 is formed on the reverse side.
When a liquid sample is analyzed by using the above analytical slide 1, the liquid sample is spotted on the multilayer analytical element 2 through the opening for spotting 3. The element after spotting is incubated, for example, at 37.degree. C. for 6 minutes to react sufficiently. Then, light is projected onto the face of the multilayer analytical element of photometric side through the opening for photometry 4, and reflected light therefrom is measured to determine the content of a particular component by colorimetry.
The analyzer for such an analytical slide is required of accuracy and simple operation. This analyzer is composed of a spotting part for the spotting of a liquid sample on to the chemical-analytical slide, an incubator to keep warm the chemical-analytical slide and to allow the proceeding of color reaction of an analyte, and a photometric part for detecting the color reaction of the chemical-analytical slide photometrically. The setting temperature and time of the incubator are generally made variable, and suitable incubational conditions are set according to the reaction system to be utilized.
As mentioned above, since chemical-analytical slides have the openings for spotting, evaporation of the liquid sample from the chemical-analytical slide during incubation is a problem. Besides, in the case of utilizing a reaction system where a color reaction is induced by the reactive gas generated by the reaction between the analyte and reagent(s), it is a problem that the analytical value lower than the true value is obtained because of effusion of a part of the reactive gas to the outside. Thereupon, the incubator was provided with a sealing member to seal the opening for spotting in order to solve the above problem. As the material of the sealing member, a plastic was employed because of slight adsorption of the reactive gas. Since the slide placing-face of the analyzer was utilized as a heater (including cooler) for maintaining temperature of the slide constant, the sealing member was reguired to press the slide to the above slide placing-face so as to exchange heat effectively. Therefore, an urging means was attached to the sealing member.
As such an incubator, the one illustrated in FIG. 10 was employed. To this incubator 6, a slide-urging unit 8 is added. 7 represents a photometric part.
A heater (not illustrated) is embedded in the upper part of the body 9 of the incubator 6, and a cell 10 into which a chemical-analytical slide 1 is inserted is bored to penetrate thereunder in a horizontal direction. A hole for photometry 11 is also bored to penetrate from the bottom face of the cell 10, which is the slide placing-face for the slide 1, to the bottom of the incubator body 9. A sealing member 13 made of plastic is mounted in the cell 10. This sealing member 13 is always urged in the direction of the hole for photometry 11 by a coil spring 12 provided between the ceiling of the cell 10 and the sealing member 13.
The photometric part 7 is located under the hole for photometry 11, and composed of light sources 14 which transmit light to the multilayer analytical elemement 2 and light receiver 15 which receives the reflected light from the multilayer analytical element 2.
The slide-pushing unit 8 inserts a chemicalanalytical slide 1 into the cell 10 at the prescribed position and draws out the inserted slide 1 from the cell 10. This slide-pushing unit 8 is composed of a sliding face 16 which is located almost the same level as the slide placing-face of the cell 10, a guide 17 which guides the chemical-analytical slide 1 and a lever 18 which pushes the chemical-analytical slide 1 into the cell 10.
When a chemical-analytical slide 1 is incubated by using such an incubator, the chemical-analytical slide 1 spotted with a liquid sample is placed on the sliding face 16, and pushed by the lever 18. By the pushing, it moves toward the cell 10, and butts against the taper face 19 of the sealing member 13. It pushes up the sealing member 13, and slides into the cell 10. Then, it stops at the prescribed position. In this state, the sealing member 13 seals the opening for spotting 3. Furthermore, it repairs curling of the slide 1, and makes flat. The chemical-analytical slide 1 is incubated at this position, and thereafter, the color formed is measured by the photometric part 7. Then, the chemical-analytical slide 1 is further pushed by the lever 18, and pushed out of the cell 10.